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Abstract:

A dispensing system and method for delivering material to a washing
device using a capacitance sensor configuration is disclosed. The
capacitance sensor configuration allows a controller to monitor and
determine a flow rate of fluid exiting a reservoir. The dispensing system
uses the flow rate information, along with downstream conductivity
information, to control the dispensing of material. Additionally, one or
more error conditions are identified during the material delivery cycle
based at least partially on the monitored conductivity and capacitance.

Claims:

1. A capacitance sensor assembly for determining flow rate comprising: a
reservoir including an input passage, at least one retaining wall,
wherein the retaining wall includes at least one opening, the opening
having an opening size; and a fluid pooling area, wherein the input
passage, fluid pooling area, and at least one opening are coupled such
that the fluid pooling area can receive fluid from the input passage and
fluid can exit the fluid pooling area through the at least one opening; a
capacitance sensor positioned within the fluid pooling area and including
a capacitance level output operable to output a capacitance level signal
indicative of a capacitance within the fluid pooling area; and a
controller including a capacitance level input module coupled to the
capacitance level output and operable to receive the capacitance level
signal, and a flow rate module operable to indicate a flow rate of fluid
exiting through the at least one opening based on the capacitance level
signal and the opening size.

2. The capacitance sensor assembly of claim 1, wherein the capacitance
sensor assembly is coupled to a material metering device configured to
dispense a material into fluid that has exited through the at least one
opening.

3. The capacitance sensor assembly of claim 2, wherein the capacitance
sensor assembly and material metering device are coupled to a washing
device.

4. The capacitance sensor assembly of claim 2, wherein the controller
controls the material metering device to dispense the material based on a
comparison of the flow rate of fluid exiting through the at least one
opening and one or more stored flow rate threshold levels.

5. The capacitance sensor assembly of claim 1, wherein the controller is
coupled to at least one conductivity sensor operable to indicate a
conductivity level of fluid that has exited the at least one opening.

6. The capacitance sensor assembly of claim 5, wherein the controller
controls the material metering device to dispense the material based on a
comparison of the conductivity level of fluid that has exited the at
least one opening and one or more stored conductivity levels.

7. The capacitance sensor assembly of claim 1, wherein the flow rate
module is operable to determine the flow rate of fluid exiting through
the at least one opening using at least one of the capacitance level
signal as an index into a stored data table, and a formula including the
capacitance level signal, the opening size, and a fluid pooling area
size.

8. A dispensing system for a washing device comprising: a fluid supply
passage; a reservoir coupled to and downstream from the fluid supply
passage; a capacitance sensor operable to indicate a capacitance level
within the reservoir; a dispenser coupled to and downstream from the
reservoir, wherein the dispenser includes a dispensing opening; an output
passage coupled to and downstream from the dispenser; a conductivity
sensor operable to indicate a conductivity level within the output
passage; and a controller electrically coupled to the capacitance sensor,
the dispenser, and the conductivity sensor, the controller operable to
determine a fluid flow rate based on the capacitance level within the
reservoir, cause the dispenser to dispense a first material through the
dispensing opening based on a comparison of the fluid flow rate and a
flow rate threshold, and indicate an error condition based on at least
one of the comparison of the fluid flow rate and a flow rate threshold,
and a comparison of the conductivity level and a first conductivity level
threshold.

9. The dispensing system for a washing device of claim 8, wherein the
reservoir includes at least one retaining wall, wherein the at least one
retaining wall includes a least one opening, and a fluid pooling area
coupled to the fluid supply passage, wherein the fluid pooling area is
operable to receive fluid from the fluid supply passage and the
capacitance sensor is positioned within the fluid pooling area.

10. The capacitance sensor assembly of claim 9, wherein the controller is
operable to determine the flow rate of fluid exiting through the at least
one opening using at least one of the capacitance level signal as an
index into a stored data table, and a formula including the capacitance
level signal, the opening size, and a fluid pooling area size.

11. The dispensing system for a washing device of claim 8, further
comprising a valve configured to control a supply of water exiting the
fluid supply passage, wherein the valve includes an off position that
prevents water from exiting the fluid supply passage and an on position
that allows water to exit the fluid supply passage, and wherein the
controller is operable to switch the valve to the on position and to the
off position.

12. The dispensing system for a washing device of claim 11, wherein the
controller is operable to switch the valve into the off position after
the dispenser dispenses the first material, based on a comparison of the
conductivity level and a second conductivity level threshold.

13. A dispensing system for delivering a material to a receiving
component positioned downstream of the dispensing system, the dispensing
system comprising: a receptacle; a valve configured to control a supply
of water to the receptacle, the valve having an off position that
prevents water from entering the receptacle and a first on position that
allows water to enter the receptacle; a material metering device
configured to dispense a material into the receptacle; a sensor
positioned upstream from the receptacle and configured to generate a
first signal indicative of capacitance; and a controller configured to
receive the first signal from the sensor and to generate a valve control
signal and a material metering device control signal, the valve control
signal operable to toggle the valve between the first on position and the
off position, the material metering device control signal operable to
initiate a dispensing of the material, the valve control signal and the
material metering device signal being generated at least partially in
response to a comparison by the controller of the first signal to one or
more stored capacitance threshold values.

14. The dispensing system of claim 13, further comprising a condition
indicator, wherein the condition indicator is configured to be in
communication with the controller, and to indicate a delivery condition
of the dispensing system.

15. The dispensing system of claim 14, wherein the condition indicator
includes at least one of a visual indicator and an audible indicator.

16. The dispensing system of claim 13, wherein the controller is
configured to communicate with one or more other monitoring or control
systems.

17. The dispensing system of claim 13, wherein the receiving component
positioned downstream of the dispensing system is a washing device.

18. The dispensing system of claim 13, further comprising a conductivity
sensor positioned proximate to the receptacle and configured to generate
a second signal indicative of conductivity; and wherein the controller is
configured to receive the second signal from the sensor and to generate
the valve control signal and the material metering device signal based at
least partially in response to a comparison by the controller of the
second signal to one or more stored conductivity threshold values.

19. The dispensing system of claim 13, wherein the controller is
configured to toggle the valve between the first on position, the off
position, and a second on position, wherein the second on position allows
less water to enter the receptacle than the first on position.

Description:

BACKGROUND

[0001] The invention generally relates to material dispensing systems.
More specifically, the invention relates to methods and systems of
monitoring and controlling material dispensing systems.

[0002] As washing machines (e.g. dish washing machines, clothes washing
machines, etc.) have become more sophisticated, systems have been
implemented to automatically feed such machines with detergents,
sanitizers, and/or rinse aids, which may be produced in liquid,
condensed, compressed, granulated, and/or powdered form. Such materials
may be automatically delivered to a variety of types of washing machines.

SUMMARY

[0003] In one embodiment, the invention provides a capacitance sensor
assembly for determining flow rate. The capacitance sensor assembly
includes a reservoir, a capacitance sensor, and a controller. The
reservoir includes an input passage, at least one retaining wall with at
least one opening, and a fluid pooling area. Fluid is received into the
fluid pooling area via the input passage and exits the fluid pooling area
through the at least one opening. The capacitance sensor is positioned
within the fluid pooling area and includes a capacitance level output
operable to output a capacitance level signal indicative of a capacitance
within the fluid pooling area. The controller includes a capacitance
level input module coupled to the capacitance level output and operable
to receive the capacitance level signal. The controller also includes a
flow rate module operable to indicate a flow rate of fluid exiting
through the at least one opening based on the capacitance level signal
and the opening size.

[0004] In another embodiment, the invention provides a dispensing system
for a washing device including a fluid supply passage, a reservoir
coupled to and downstream from the fluid supply passage, and a
capacitance sensor operable to indicate a capacitance level within the
reservoir. The dispensing system further includes a dispenser coupled to
and downstream from the reservoir, wherein the dispenser includes a
dispensing opening, an output passage coupled to and downstream from the
dispenser, a conductivity sensor operable to indicate a conductivity
level within the output passage, and a controller. The controller is
electrically coupled to the capacitance sensor, the dispenser, and the
conductivity sensor. Furthermore, the controller is operable to determine
a fluid flow rate based on the capacitance level within the reservoir, to
cause the dispenser to dispense a first material through the dispensing
opening based on a comparison of the fluid flow rate and a flow rate
threshold, and to indicate an error condition. The error condition may be
based on at least one of the comparison of the fluid flow rate and a flow
rate threshold and a comparison of the conductivity level and a first
conductivity level threshold.

[0005] In another embodiment, the invention provides a dispensing system
for delivering a material to a receiving component positioned downstream
of the dispensing system. The dispensing system including a receptacle, a
valve, a controller, a material metering device configured to dispense
material into the receptacle, and a sensor positioned upstream from the
receptacle and configured to generate a first signal indicative of
capacitance. The valve is configured to control a supply of water to the
receptacle, the valve having an off position that prevents water from
entering the receptacle and a first on position that allows water to
enter the receptacle. The controller is configured to receive the first
signal from the sensor and to generate a valve control signal and a
material metering device control signal. The valve control signal is
operable to toggle the valve between the first on position and the off
position. The material metering device control signal is operable to
initiate a dispensing of the material. The valve control signal and the
material metering device signal are generated at least partially in
response to a comparison by the controller of the first signal to one or
more stored capacitance threshold values.

[0006] Other aspects of the invention will become apparent by
consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 illustrates an exemplary dispensing system according to an
embodiment of the invention.

[0008]FIG. 2 is a block diagram of an exemplary control system according
to an embodiment of the invention.

[0009] FIG. 3 illustrates an exemplary process for controlling operations
of a dispensing system according to an embodiment of the invention.

[0010]FIG. 4A illustrates an exemplary capacitance sensor assembly
according to an embodiment of the invention.

[0011]FIG. 4B illustrates an exemplary process for controlling operations
of a capacitance sensor assembly according to an embodiment of the
invention.

[0012] FIGS. 5A-D illustrate an exemplary operation of a capacitance
sensor assembly according to an embodiment of the invention.

[0013] FIG. 6 illustrates an exemplary embodiment of a condition indicator
according to an embodiment of the invention.

[0014]FIG. 7 illustrates an exemplary dispensing system according to an
embodiment of the invention.

[0015]FIG. 8 illustrates an exemplary embodiment of a dispensing closure
according to an embodiment of the invention.

[0016]FIG. 9 illustrates an exemplary dispensing system according to
another embodiment of the invention.

[0017] FIG. 10 illustrates an exemplary dispensing system according to yet
another embodiment of the invention.

DETAILED DESCRIPTION

[0018] Before any embodiments of the invention are explained in detail, it
is to be understood that the invention is not limited in its application
to the details of construction and the arrangement of components set
forth in the following description or illustrated in the following
drawings. The invention is capable of other embodiments and of being
practiced or of being carried out in various ways. Also, it is to be
understood that the phraseology and terminology used herein are for the
purpose of description and should not be regarded as limiting. The use of
"including," "comprising," or "having" and variations thereof herein is
meant to encompass the items listed thereafter and equivalents thereof as
well as additional items. Unless specified or limited otherwise, the
terms "mounted," "connected," "supported," and "coupled" and variations
thereof are used broadly and encompass both direct and indirect
mountings, connections, supports, and couplings. Further, "connected" and
"coupled" are not restricted to physical or mechanical connections or
couplings.

[0019] As should also be apparent to one of ordinary skill in the art, the
systems shown in the figures are models of what actual systems might be
like. Many of the modules and logical structures described are capable of
being implemented in software executed by a microprocessor or a similar
device or of being implemented in hardware using a variety of components
including, for example, application specific integrated circuits
("ASICs"). Terms like "controller" may include or refer to both hardware
and/or software. Furthermore, throughout the specification capitalized
terms are used. Such terms are used to conform to common practices and to
help correlate the description with the coding examples, equations,
and/or drawings. However, no specific meaning is implied or should be
inferred simply due to the use of capitalization. Thus, the claims should
not be limited to the specific examples or terminology or to any specific
hardware or software implementation or combination of software or
hardware.

[0020] Embodiments of the invention provide methods and systems of
monitoring and controlling material dispensing systems that
automatically, accurately, and efficiently, deliver material to a variety
of types of washing machines. For instance, a capacitance sensor assembly
improves the ability of a dispensing system to monitor the flow of water
or fluid through the dispensing system. In particular, water may be
filtered or distilled to the point where a conductivity sensor's ability
to detect water is degraded or ineffective. Use of the capacitance sensor
of the present invention advantageously results in water and flow rate
detection that is less affected than other types of sensors by water's
ionization level, softness level, and amount of filtering (e.g., by
reverse osmosis or other processes).

[0021] In addition, embodiments of the capacitance sensor assembly provide
beneficial information to a control system for a dispensing system beyond
the detection of water. For instance, the capacitance sensor assembly
output signals can be used to determine the flow rate of water through
the capacitance sensor assembly. Thus, the control system more accurately
determines when to dispense material, the quantity of material to
dispense, and when an error condition is present.

[0022] FIG. 1 depicts components of one exemplary embodiment of a
dispensing system 100 for a downstream washing device. A controller 106
is used to monitor and control the dispensing system 100. The controller
106 includes an input/output module 107 and a flow rate module 108. The
controller 106 is electrically coupled via the input/output module 107 to
the solenoid valve 104, capacitance sensor assembly 110, dispenser 134,
and conductivity sensor 142. Using the input/output module 107, the
controller 106 receives measurements from the capacitance sensor assembly
110 and conductivity sensor 142, and outputs control signals to the
solenoid valve 104 and dispenser 134. The water intake conduit 102 is
coupled to a solenoid valve 104 controlled by the controller 106. The
water intake conduit 102 and solenoid valve 104 are used to introduce
water into the dispensing system 100. For example, in some embodiments,
when the solenoid valve 104 is energized, water from the water intake
conduit 102 is allowed to enter the dispensing system 100. Alternatively,
when the solenoid valve 104 is de-energized, water is prevented from
entering the dispensing system 100. In other embodiments, a valve
mechanism other than the solenoid valve 104 may be used.

[0023] When the solenoid valve 104 is set to allow water to flow into the
dispensing system 100, water flows into the capacitance sensor assembly
110. The capacitance sensor assembly 110 is configured to measure a
capacitance level of the contents (e.g., air and/or water) therein and to
output a signal indicative of the capacitance level to the input/output
module 107 of the controller 106. This capacitance level is indicative of
the amount of water within the capacitance sensor assembly 110, which can
be used by the flow rate module 108 to determine the flow rate of the
water. An exemplary capacitance sensor assembly 110 is shown in more
detail in FIG. 4A. Water flowing into the capacitance sensor assembly 110
from the water intake conduit 102 proceeds to flow into the water channel
118.

[0024] The funnel 130 receives water flowing out of the water channel 118
in addition to material dispensed from the container 132 by the dispenser
134. As will be explained in further detail below, the dispenser 134 is
controlled by the controller 106 to dispense a particular amount of
material from the container 132 at particular instances.

[0025] The channel 140 is fluidly coupled to the funnel 130 to receive the
contents of the funnel 130. The downstream washing device (not shown) is
fluidly coupled to the channel 140 to receive the contents of the channel
140. The conductivity sensor 142 is attached to the channel 140 to
measure the conductivity of the contents of the channel 140. If no water
or dispensing material is in the channel 140, the conductivity sensor 142
will measure and output a low conductivity level. If only water is
present in the channel 140, the conductivity sensor 142 will measure and
output a higher conductivity level than if no water or material is
present. If a combination of water and a dispensed material from
container 132 is present in the channel 140, the conductivity sensor 142
will measure and output a conductivity level that is higher than both the
empty channel 140 and water-only channel 140 conductivity levels. Water
that has been deionized or filtered (e.g., by reverse osmosis) may not be
detected by the conductivity sensor 142. When the conductivity sensor 142
cannot properly detect water, the capacitance sensor assembly 110 can be
relied upon to ensure proper flow rate of water entering the funnel 130.
While a conductivity sensor 142 is present in this embodiment of the
invention, other embodiments do not include a conductivity sensor.

[0026]FIG. 2 is a block diagram of an exemplary control system 200. In
some embodiments, the control system 200 can be used, for example, to
control the components described with respect to the dispensing system
shown in FIG. 1. Generally, the control system 200 utilizes a controller
106 to operate a solenoid valve 104, a material metering device 134, and
a dispensing system condition indicator 220. Additionally, the controller
106 receives information from the conductivity sensor 142 and the
capacitance sensor assembly 110. The controller 106 may communicate with,
control, and receive signals with other components via the input/output
module 107.

[0027] Generally, the controller 106 is a suitable electronic device, such
as, for example, a programmable logic controller ("PLC"), a personal
computer ("PC"), and/or other industrial/personal computing device. As
such, the controller 106 may include both hardware and software
components, and is meant to broadly encompass the combination of such
components. In some embodiments, the solenoid valve 104 is a normally
closed valve that opens when energized, which occurs when the controller
106 transmits a signal to the solenoid valve 104 to open the solenoid
valve 104. The material metering device 134 is used to control the amount
of material that is dispensed from a container. Similar to the solenoid
valve 104, the metering device 134 is controlled via a signal from the
controller 106. The condition indicator 220 can include one or more
visual and/or audible indicators (e.g., a light, a liquid crystal display
("LCD") unit, a horn, etc.) to indicate to a user a condition of the
dispensing system (e.g., as described with respect to FIG. 6).

[0028] In some embodiments, the conductivity sensor 142 is an analog
conductivity sensor that transmits a variable signal (e.g., a 0-10 volt
signal, a 0-10 milliamp signal, etc.) to the controller 106 that is
indicative of the conductivity of the area surrounding the sensor 142. In
some embodiments, the capacitance sensor assembly 110 is an analog
capacitance sensor that transmits a variable signal (e.g., a 0-10 volt
signal, a 0-10 milliamp signal, etc.) to the controller 106 that is
indicative of the capacitance level of the area surrounding the
capacitance sensor assembly 110. The flow rate module 108 of the
controller 106 can use the capacitance level signal, in conjunction with
other known variables, to determine the flow rate of water out of the
area surrounding the capacitance sensor assembly 110.

[0029] In operation, generally, the controller 106 utilizes the
information from the sensors 142 and 110 to determine how to control the
solenoid valve 104, the metering device 134, and the dispensing system
condition indicator 220. For example, in some embodiments, during a
material delivery cycle (e.g., a cycle in which one or more doses of
material are dispensed), the controller 106 initially transmits a signal
to the solenoid valve 104 to energize the solenoid valve 104. Once
energized, the solenoid valve 104 allows water to flow. This initial
influx of water can be referred to as a pre-flush. Additionally, the
controller 106 receives capacitance information via a signal from the
capacitance sensor assembly 110 and conductivity information via a signal
from the conductivity sensor 142. The controller 106 utilizes the
capacitance and conductivity information to determine whether to dispense
one or more doses of material into the flowing water. If the controller
106 determines not to dispense the material, for instance, because the
capacitance sensor assembly 110 or conductivity sensor 142 indicates that
no water or a low amount of water is present, the controller 106 may
generate a dispensing error condition signal. The dispensing error
condition signal is transmitted to the condition indicator 220, which
then indicates the error.

[0030] After dosing, the controller 106 keeps the solenoid valve 104
energized to allow the flowing water to clear away the delivered
material. This water flow after dosing can be referred to as a
post-flush. Following and/or during the post-flush, the controller 106
also uses the capacitance information from the capacitance sensor
assembly 110 to verify the water flow rate and uses conductivity
information from the conductivity sensor 142 to verify that the material
was properly administered and/or received by downstream components. If
the controller 106 determines that the material was not properly
administered and/or received by downstream components, or that the water
flow rate is incorrect, the controller 106 may generate a dispensing
error condition signal that is transmitted to the condition indicator
220, which then indicates the error.

[0031] In some embodiments, the control system 200 may include an input
device that allows a user to input and control one or more
user-changeable settings. For example, a user may use the input device to
enter a material amount (e.g., a number of doses to deliver), a length
and/or amount of pre-flush, and a length and/or amount of post-flush. In
some embodiments, for example, the pre-flush is adjustable between
approximately 1.5 and 5 seconds in duration and the post-flush is
adjustable between approximately 2 and 10 seconds in duration.
Additionally, a user may enter one or more conductivity thresholds and/or
capacitance thresholds, which the controller 106 can store and use to
decide whether to deliver the material.

[0032] In some embodiments, the control system 200 does not include a
conductivity sensor 142 and relies on a closed-loop feedback system
involving the capacitance sensor assembly 110. In such embodiments, the
valve is opened or closed to maintain a desired flow rate as measured by
the capacitance sensor assembly 110. In other embodiments, the control
system 200 may contain more components than those shown in FIG. 2. In one
embodiment, the control system 200 includes multiple sensors for
measuring conductivity at different locations in a dispensing system. For
example, a downstream sensor can be added to the control system 200 that
measures the conductivity of the water/material solution after the
solution has exited the channel 140 (e.g., in a clothes or dish washing
machine). In another embodiment, the control system 200 may include a
communication device that allows the control system 200 to communicate
with other systems. For example, in some embodiments, the control system
200 tracks the amount of material that is available to be dispensed, and
transmit a notification signal to another system when the material level
is low. The control system 200 may also transmit operational information
(e.g., dosage amount, length of pre-flush and post-flush, dispensing
system errors, etc.) to one or more other systems (e.g., a central
control system). Additionally, the control system 200 may be operated by
another system via the communication system.

[0033] In some embodiments, the controller 106 may generate a dispensing
error condition signal for reasons other than those described above. For
example, in embodiments that include more than one sensor (e.g., one
capacitance sensor assembly 110 positioned proximate to a water intake
conduit and one conductivity sensor 142 positioned near an outlet
conduit), the controller 106 may generate a dispensing error condition
signal if the signals from the sensors are not consistent. For example,
if the capacitance sensor assembly 110 that is proximate to the water
intake conduit indicates that water is flowing, but the conductivity
sensor 142 that is proximate to the outlet conduit does not indicate that
water is present, a dispensing error condition may be identified. In
another embodiment, an error condition signal may be generated if a
problem with the communication system is identified (e.g., the
communication system is unable to transmit information to other systems).

[0034] FIG. 3 illustrates a process 300 for controlling the operations of
a dispensing system (e.g., the dispensing system 100) using a control
system (e.g., the control system 200) during a material delivery cycle.
In some embodiments, the process 300 can also be used to verify that a
material has been properly delivered, as well as provide an indication of
how much material has been delivered. While the process 300 is described
as being carried out by the components included in the dispensing system
100 and/or the control system 200, in other embodiments, the process 300
can be applied to other systems. In some embodiments, the process 300 is
performed multiple times to effect one complete washing cycle of the
washing device. For instance, process 300 may be performed once for
dispensing detergent material, once for dispensing sanitizer material,
and once for dispensing rinse aid material.

[0035] The first step in the process 300 is to begin measuring capacitance
in the capacitance sensor assembly 110 and conductivity in the
conductivity sensor 142 (step 305) by initializing each sensor. In some
embodiments, the capacitance sensor assembly 110 and/or conductivity
sensor 142 are in constant operation, generating and transmitting signals
indicative of capacitance or conductivity to the controller 106, and do
not need to be initialized. In some embodiments, the controller 106 uses
the capacitance level signal to determine a water flow rate exiting the
capacitance sensor assembly 110 into the water channel 118. Next, water
is supplied to the funnel 130 for a pre-flush operation (step 310), and a
change in conductivity and capacitance is verified (step 315). For
example, the controller 106 verifies that the conductivity monitored by
the conductivity sensor 142 changes and the capacitance monitored by the
capacitance sensor assembly 110 changes when water is added. The
controller 106 can verify or determine that the conductivity changes are
appropriate by comparing the conductivity signal from the sensor 142 to a
stored set of conductivity thresholds. The controller 106 can verify or
determine that the capacitance changes are appropriate by comparing the
capacitance signal from the capacitance sensor assembly 110 to a stored
set of capacitance thresholds.

[0036] The comparison of conductivity values to conductivity thresholds
and capacitance values to capacitance thresholds can also aid in
determining whether a dispensing error condition is present. For example,
if the conductivity that is monitored by the conductivity sensor 142 does
not change in accordance with bounds or thresholds set in the controller
106 pertaining to a material delivery cycle, a dispensing error condition
may be indicated (e.g., displayed by the condition indicator 220) (step
320). Additionally in step 320, if the capacitance level that is
monitored by the capacitance sensor assembly 110 does not change in
accordance with bounds or thresholds set in the controller 106 pertaining
to a material delivery cycle, a dispensing error condition may be
indicated (e.g., displayed by the condition indicator 220). For example,
in some embodiments, the condition indicator 220 indicates a dispensing
error condition using an array of lights (e.g., as described with respect
to FIG. 6). In another embodiment, as previously described, the condition
indicator 220 indicates a dispensing error condition using an LCD unit or
similar visual device. Additionally or alternatively, an audible alarm
may be used to indicate a dispensing error condition, or a message may be
sent. As described in greater detail below, dispensing error conditions
may include a "no water" condition, a "blocked funnel" condition, or an
"out of product" condition. Other dispensing error conditions are also
possible (e.g., a "drive failure" condition, a "solenoid valve failure"
condition, etc.)

[0037] Referring still to FIG. 3, if the conductivity monitored by the
conductivity sensor 142 changes in accordance with the thresholds set in
the controller 106 and the flow rate determined by the controller 106
using the capacitance level signal from the capacitance sensor assembly
110 is maintained between thresholds set in the controller 106, the
controller 106 then determines whether to dispense one or more doses of
material (step 325). If the controller 106 determines not to dispense the
material, a dispensing error condition may be indicated (step 330). Such
a determination may be made, for example, if there is a change in
conductivity monitored by the sensor 142, but the change is not
consistent with certain conductivity thresholds. Another such
determination may be made if, for example, using the capacitance sensor
assembly 110, the controller 106 determines that the flow rate is below a
low level threshold or above a high level threshold set in the controller
106.

[0038] If the controller 106 determines to dispense one or more doses of
material, such doses are dispensed (step 332), and the next step in the
process 300 is to determine if the conductivity monitored by the sensor
142 changes appropriately after dosing (step 335). If the change in
conductivity is not appropriate, or there is no change in conductivity, a
dispensing error condition may be indicated (step 337). The capacitance
sensor assembly 110 is also monitored in step 335 to determine if the
water flow rate drops below a low level threshold or rises above a high
level threshold set in the controller 106. If the flow rate is too high
or too low relative to the thresholds, a dispensing error condition may
be indicated as well (step 337).

[0039] If the conductivity change is appropriate and the flow rate is
appropriate, delivery of the material is completed and a post-flush
operation is initiated (step 340), and a final conductivity change is
verified and water flow rate is verified (step 345). If the final change
in conductivity is not appropriate, or there is no change in
conductivity, a dispensing error condition may be indicated (step 350).
If the water flow rate drops below a low level threshold or rises above a
high level threshold set in the controller 106, a dispensing error
condition may be indicated as well (step 350). If the change in
conductivity and the water flow rate is appropriate, the process 300 ends
(step 355), and the material delivery cycle is complete. Upon completion,
the controller 106 can determine or verify that the material has been
properly delivered. The controller 106 can also determine how much
material was delivered by determining how many doses were delivered
(e.g., see step 332). The process 300 is completed each time a material
delivery cycle is initiated.

[0040] In other embodiments, an alternative process may be used to deliver
the material to the washing device. For instance, if the controller 106
determines in a flow rate verification step (e.g., steps 315, 335, or
345) that the flow rate is above a high threshold or below a low
threshold, the controller 106, instead of initiating an error condition,
may adjust the solenoid valve to alter the flow rate to be within an
acceptable range. The controller 106 can perform this adjustment by, for
example, further closing or further opening the solenoid valve 104.
Furthermore, in some embodiments, conductivity or capacitance may be
verified at additional points during the process. For instance, an
additional capacitance sensor assembly 110 may be placed just after the
channel 140 output, but before the washing device input (not shown), to
determine the output flow rate of fluid. Additionally or alternatively,
other parameters may be monitored (e.g., material weight, inductance,
turbidity, etc.) and used to determine if one or more doses of material
should be delivered and/or if the doses were properly received.

[0041] One embodiment of the capacitance sensor assembly 110 of FIG. 1
will be described in further detail with respect to FIG. 4A. In FIG. 4A,
the capacitance sensor assembly 110 includes a reservoir 412 formed by a
base 411 and retaining walls 413 and 414. Although base 411, retaining
walls 413 and 414, and water channel 118 are separately labeled, they may
be a single unitary construction or formed from a plurality of pieces.
Two parallel plates are positioned within the reservoir 412 to form a
capacitance sensor 416. The capacitance sensor assembly 110 includes an
input/output connector 430 to be electrically coupled to a controller 106
to indicate a measured capacitance level. The retaining wall 414 has an
opening 420 with a known size that fluidly couples the reservoir 412 to
the water channel 118. The opening 420 may also be referred to as a weir.
The water flowing into the reservoir 412 from a water intake conduit 102
proceeds to flow out of the reservoir 412 via an opening 420 into the
water channel 118. In one embodiment, the opening 420 has a rectangular
shape with a height h and width w. An alternative opening shape and/or
multiple openings can also be used in other embodiments. Although the
reservoir 412 is shown to have a partially circular base 411, other
constructions are possible in other embodiments. For example, a
rectangular base or other base shape may be used. Furthermore, the base
411 and retaining walls 413 and 414 need not intersect perpendicularly.
The base 411 may be attached to the retaining walls 413 and 414 at an
angle generally sloping towards the opening 420 to encourage water to
flow towards the opening 420.

[0042] The controller 106 of FIG. 1 can calculate the flow rate of water
exiting the reservoir 412 to the water channel 118 using the capacitance
measurement of the capacitance sensor 416 sent via the input/output
connector 430. As water flows into the reservoir 412, particularly when
the incoming flow rate is greater than the amount of water flowing out of
the opening 420, water will pool behind the retaining walls 413 and 414.
The capacitance sensor 416 measures and outputs the capacitance level
between its two parallel plates. An increase in capacitance measured by
the capacitance sensor 416 indicates an increase in the water level
within the reservoir 412. As the water level increases, the flow rate of
water exiting the reservoir 412 via the opening 420 increases. In one
embodiment, a database stored in a memory of the controller 106 includes
previously measured or estimated flow rates based on fluid levels within
the reservoir 412, and the flow rate module 108 uses capacitance levels
as index values to reference the associated flow rates. In another
embodiment, the controller 106 can be preset or receive as user input the
dimensions of the reservoir 412, including the base wall 411, the
retaining walls 413 and 414, and the opening 420. Thereafter, the flow
rate module 108 calculates the flow rate of water exiting the reservoir
412 to the water channel 118 using the capacitance measurement of the
capacitance sensor 416 and the known dimensions of the reservoir 412.

[0043] In the embodiment shown in FIG. 4A, the parallel plates of the
capacitance sensor 416 extend down to contact the base 411. In this
embodiment, the capacitance sensor 416 outputs a capacitance level that
increases as the water level rises in the reservoir 412. In another
embodiment, the parallel plates of the capacitance sensor 416 do not
extend down to contact the base 411. Rather, the parallel plates are
attached to the retaining wall 412, to a cover portion that is atop the
retaining wall 412, or to another securing means, such that the bottoms
of the parallel plates are floating above the base 411. The floating
height is chosen such that when the water level reaches the bottom of the
parallel plates, the minimum necessary flow rate is reached. The
capacitance sensor 416 will output at least two capacitance levels: a
first capacitance level indicating that only air is between the parallel
plates and a second capacitance level indicating that water is between
the parallel plates (i.e., the water level has reached the bottom of the
parallel plates). As such, the capacitance sensor assembly 110 operates
as a "go/no-go" gauge that informs the control system 200 whether the
minimum water flow rate is met.

[0044] To calculate the flow rate exiting the capacitance sensor assembly
110 based on the height of the water level therein, the following
equation and variables may be used:

Q=0.66×cB×(2g)0.66×H1.5

Q=water flow rate (m3/sec)

B=width of the opening 420(m)

c=discharge coefficient

g=gravitational constant (m/s2)

H=height of the water over the opening 420, measured behind the opening
420 edge (m)

[0045] In one embodiment, the discharge coefficient (c) can have a value
of approximately 0.62. The gravitational constant (g) can have a value of
approximately 9.81 m/s2. If the area behind the opening 420 where
water pools is narrower than the width of the opening 420, the equation
for B becomes: B=width of the opening 420-(0.2×H). The area behind
the opening 420 where water pools in FIG. 4A, however, is wider than the
width of the opening 420. Thus, no adjustments to the value of B are
required for flow rate calculations of the capacitance sensor assembly
110 depicted in FIG. 4.

[0046] A method of operation of the capacitance sensor assembly 110 of
FIG. 4A will be described in further detail with respect to FIGS. 4B and
5A-5D. FIG. 4B illustrates a process 450 for controlling the operations
of a capacitance sensor assembly system (the capacitance sensor assembly
110 of FIG. 4A). While the process 450 is described as being carried out
by the components included in the capacitance sensor assembly 110, in
other embodiments, the process 300 can be applied to other systems.

[0047] The first step in the process 450 is to load the controller 106
with the appropriate known variable values. For instance, variable values
to load may include reservoir 412 dimensions and capacitance threshold
values. Next, in step 460, the controller 106 initializes the capacitance
sensor 416, if the capacitance sensor is of the type requiring
initialization. In some embodiments, the capacitance sensor 416
continuously outputs signals indicative of a capacitance level without
the need for initialization. Thereafter, the capacitance sensor 416
measures the capacitance within the reservoir 412 and outputs values to
the controller 106 (step 465). The capacitance within the reservoir 412
is indicative of the water level therein. The controller 106 then
receives the capacitance signals and calculates the flow rate of fluid
exiting the reservoir 412 (step 475). In step 480, the controller 106
determines whether to continue to monitor the capacitance level within
the reservoir 412 and calculate the flow rate. If the controller 106
determines to continue monitoring and calculating, the process returns to
step 465. Otherwise, the process ends at step 485.

[0048] FIG. 5A includes a graph 500 showing the relationship between (1)
the fluid level within the reservoir 412 and (2) the capacitance level
signal output by the capacitance sensor 416 and the fluid flow rate
exiting the reservoir 412. Three points, 505, 510, and 515, are displayed
on the graph 500. The three points depict that, as the fluid level in the
reservoir increases, both the capacitance level indicated by the
capacitance sensor 416 and the determined fluid flow rate out of the
reservoir 412 also increase.

[0049] An exemplary low flow rate threshold 501 and high flow rate
threshold 502 are also depicted in FIG. 5A. Thresholds 501 and 502 may be
stored in the controller 106 and used in the process of FIG. 3 to
determine if the flow rate of water exiting the capacitance sensor
assembly 110 is appropriate. FIG. 5B depicts the capacitance sensor 416
and reservoir base 411 where too little fluid is flowing through the
capacitance sensor assembly 110. This low-fluid scenario is graphically
depicted as point 505 in FIG. 5A. FIG. 5C depicts the capacitance sensor
416 and reservoir base 411 where an appropriate level of fluid is flowing
through the capacitance sensor assembly 110. This scenario is graphically
depicted as point 510 in FIG. 5A. FIG. 5D depicts the capacitance sensor
416 and reservoir base 411 where too much fluid is flowing through the
capacitance sensor assembly 110. This scenario is graphically depicted as
point 515 in FIG. 5A.

[0050] Although only two thresholds are shown in FIG. 5A, the controller
106 may have more thresholds stored such that different high and low
thresholds are used, for instance, at each stage in the process of FIG. 3
being performed. For instance, in one embodiment, a lower pre-flush flow
rate relative to the post-flush flow rate may be desired; thus, the high
and low flow rate thresholds are lower for the pre-flush operation than
for the post-flush operation.

[0051] FIG. 6 illustrates an exemplary embodiment of a condition indicator
600 for a dispensing system, such as the dispensing system 100, that
includes three materials (e.g., a detergent material, a sanitizer
material, and a rinse aid material). In other embodiment, the condition
indicator 600 may be adapted to a system that includes more or fewer
materials than those shown in FIG. 6. The condition indicator 600
generally includes a detergent material indicator light element 605, a
sanitizer material indicator light element 610, and a rinse aid material
indicator light element 615 that correspond to the three materials.
Additionally, in some embodiments, the condition indicator 600 includes a
message display (e.g., an LCD or similar type of display). In other
embodiments, the condition indicator 600 can include more or fewer lights
(or other indicating components) than those shown in FIG. 6. For example,
in some embodiments, the condition indicator 600 may include additional
light elements (e.g., a plurality of different colored light elements).
Alternatively, the condition indicator 600 may include fewer light
elements (e.g., a single light element that changes color).

[0052] Generally, the light elements 605-615 can be used to indicate a
condition of the dispensing system and/or a status of each material. For
example, in one embodiment, as described in greater detail below, the
light elements 605-615 change color according to the condition of the
dispensing system. For example, a green light can indicate that the
dispensing system is operating properly. However, if an error condition
is identified, the light may change color to indicate to a user that an
error condition is present.

[0053] For example, in one embodiment, after an error condition has been
identified (e.g., a "blocked receptacle" condition), a yellow flashing
light is used to indicate that the material dispensing system has been
disabled (i.e., material will not be dispensed during a dosing period).
In order to clear the error condition and continue with dispensing system
operation, power to the dispensing system 100 may have to be removed and
then restored. In other embodiments, the error condition may be cleared
using another method, for example, with an input device located on the
face of the condition indicator (e.g., a "clear fault" pushbutton).

[0054] In some embodiments, the dispensing system is not disabled until
after a certain number of errors or faults have been identified, or after
a predetermined time period has elapsed. For example, a controller can
register and/or store identified error conditions as they are identified,
and disable the dispensing system after three consecutive error
conditions. Such embodiments can minimize disabling of the dispensing
system due to faulty identified error conditions.

[0055]FIG. 7 illustrates an exemplary dispensing system 700 that can
include or replace some components of dispensing system 100 of FIG. 1,
not all of which are shown in FIG. 7. In some embodiments, the dispensing
system 700 is configured to dispense or deliver a granulated material or
powder (e.g., a chemical such as a detergent, a sanitizer, a rinse aid,
etc.). For example, in some embodiments, a granular or powder material is
delivered to a clothes washing machine. In other embodiments, a granular
or powder material is delivered to a dish washing machine. In the
embodiment shown in FIG. 7, the dispensing system 700 generally includes
a granulated material or powder container 705 that is supported in a
dispenser assembly or receptacle 710. The container 705 is closed on one
end by a metering and dispensing closure 715, which, as described in
greater detail with respect to FIG. 8, can deliver or dose a
predetermined amount of material from the container 705 into the
receptacle 710. For example, in one embodiment, the dispensing closure
715 is rotated by a drive shaft 720 to deliver the material. The drive
shaft 720 is driven by a drive member 725, and is journalled in a collar
730 with a seal 735.

[0056] The dispensing system 700 also includes a water intake conduit 740
that is controlled by a solenoid valve 745. The water intake conduit 740
and solenoid valve 745 are utilized to introduce water into the
receptacle 710. For example, in some embodiments, when the solenoid valve
745 is energized, water from the water intake conduit 740 is allowed to
enter the receptacle 710. Alternatively, when the solenoid valve 745 is
de-energized, water is prevented from entering the receptacle 710. In
other embodiments, a valve mechanism other than the solenoid valve 745
may be used, such as one controlled by a stepper motor or pulse width
modulation (PWM) controller. In these embodiments, a valve can have a
number of set positions, such as closed, 25% open, 50% open, 75% open,
and 100% open, up to as many as the chosen valve controller will allow.

[0057] A water solution outlet conduit 750 is also in communication with
the receptacle 710. For example, the outlet conduit 750 allows water to
exit the receptacle 710. In some embodiments, as described in greater
detail below, water is mixed with dispensed material prior to exiting the
receptacle 710 through the outlet conduit 750. In the embodiment shown in
FIG. 7, liquid or solution is allowed to exit the receptacle 710 through
the outlet conduit 750 relatively unobstructed. In other embodiments, the
outlet conduit 750 may include a solenoid valve or other valve, similar
to the solenoid 745.

[0058] In some embodiments, as described in greater detail below, the
dispensing system 700 can also include electronic components such as a
controller 106, one or more conductivity sensors 142, and one or more
capacitance sensor assemblies 110. For example, in one embodiment, one or
more conductivity sensors are positioned in the receptacle 710 to monitor
the conductivity of the receptacle 710 (and the liquid disposed therein).
In addition, in one embodiment, a capacitance sensor assembly 110 is
fluidly coupled between the output of the water intake conduit 740 and
the receptacle 710.

[0059] As shown in FIG. 8, the metering and dispensing closure 715 is
generally composed of three basic components. For example, the closure
715 generally includes a cap member 800 with an upstanding wall 805 and
internal threads 810 for engaging complementary threads on the container
705. The second component is a rotatable disk 815 with a raised
peripheral wall 820, as well as a cutaway portion 825. Rotatable disk 815
is configured to be seated inside the cap member 800. The third component
is a rotatable disk 830 with a raised peripheral wall 835 and a stub
shaft 840 with projections 845. These projections 845 fit through an
opening 850 in the cap member 800 in a manner that the projections 845
engage slots 855 in the rotatable disk 815. Rotatable disks 815 and 830
are rotated by the shaft 720 (see FIG. 7) connected to the stub shaft
840.

[0060] Referring to FIGS. 7 and 8, in operation, the container 705 holding
the material is supported in the receptacle 710. Water is introduced into
the receptacle 710 through the water intake conduit 740. The metering and
dispensing closure 715 is attached to the container 705. When the disks
815 and 830 of the closure 715 are properly aligned, the material from
the container 705 is free to enter into a measuring opening or chamber
860 as it is uncovered by disk 815 and cutaway 825 (see FIG. 8). However,
the material from the container 705 cannot pass into the receptacle 710,
as the passage is blocked by rotatable disk 830. Activation of the drive
member 725 and rotation of the drive shaft 720 causes the upper rotatable
disk 815 and the lower rotatable disk 830 to move to a second position in
which no more material can enter the opening 860, which has become a
measuring chamber. Continued rotation of the disks 815 and 830 allows for
the opening 860 to be positioned over opening 870, which allows the dose
of material from the measuring chamber to flow into the receptacle 710
and be mixed with water from the intake conduit 740. The mixed material
then exits the receptacle 710 through the water solution outlet conduit
750. In some embodiments, multiple doses are delivered during a single
delivery cycle.

[0061] Referring to FIGS. 9 and 10, additional embodiments of dispensing
systems are shown. In the embodiments shown in FIGS. 9 and 10, components
similar to, or the same as, the components shown in FIGS. 7 and 8 are
labeled with like numerals. For example, FIG. 9 illustrates a dispensing
system 900 that includes two containers 705. In some embodiments, the
separate containers 705 are utilized to introduce separate powder
materials (e.g., a sanitizer and a detergent) to the water supply. FIG.
10 illustrates another embodiment of a dispensing system 1000 that
includes an alternative type of container 705. The dispensing systems
described with respect to FIGS. 7-10 are provided as exemplary systems
only. It should be understood that the control methods described with
respect to FIGS. 1-6 may be applied to a variety of dispensing systems.
For example, in other embodiments, a dispensing system need not include a
receptacle that contains water. An alternative dispensing system may
utilize a separate portion that allows a material to be dropped into an
additional container having a liquid predisposed therein. Additionally or
alternatively, other liquids such as water miscible and immiscible
solvents including water and ether could be employed in a dispensing
system.

[0062] Thus, the invention provides, among other things, methods and
systems of operating and controlling material dispensing systems. Various
features and advantages of the invention are set forth in the following
claims.